Washington: Two missing species of shark were discovered in a new analysis of weapons made from shark teeth and used by 19th century islanders.
The Gilbert Island reefs in the Central Pacific were once home to these two species of sharks not previously reported in historic records or contemporary studies.
Sharks were culturally important to the Gilbertese Islanders; historic records indicate a complex ritual system surrounding shark fishing and making fishing gear and weapons from shark teeth.
For the current study, Joshua Drew from Columbia University and colleagues from the Field Museum of Natural History analyzed a collection of 120 of these weapons from the Field Museum of Natural History, including some that resemble clubs, daggers, lances, spears and swords.
They identified eight species of sharks based on the teeth used in these weapons, two of which have never been reported from these waters, in either historical surveys or contemporary analysis.
Both these species are currently common in other areas, so while it is possible that these species may still be living undiscovered in the Gilberts, it is more likely that the local populations have been driven to extinction.
The study is published in the open access journal PLOS ONE.